1. Field of the Invention
The present invention relates to a chair structure, and especially relates to a topple-proof buffering structure for the chair.
2. Description of Related Art
I the field of chair, the sitting feeling and comfort of a seat of a chair is gradually requested due to the improvement of the technical skills. Therefore, an elastic buffering structure is designed within the seat of the chair.
Please reference to U.S. patent no. 2014/0252824 A1 (hereafter referred to '824), the structure is shown as in FIG. 6. Four rubber bushings (400, FIG. 6 of '824) are arranged between a lower base plate (330, FIG. 6 of '824) arrange at an upper end of a chair leg (310, FIG. 6 of '824) and an upper seat plate (220, FIG. 6 of '824) arranged at a bottom surface of a chair seat (210, FIG. 6 of '824). Two ends of each rubber bushing (400, FIG. 6 of '824) are connected with two connectors (nipples 404, FIG. 6 of '824) having bolt(s) or screw(s) and used to provide the lower base plate (330, FIG. 6 of '824) to connect to the upper seat plate (220, FIG. 6 of '824) so as to form the structure shown as in FIG. 8 of '824. The chair seat (210, FIG. 6 of '824) is supported by the elastic deformation of the rubber bushing bodies (402, FIG. 6 of '824) so as to form multi-directional moving elastic buffering.
However, the chair structure with multi-directional moving elastic buffering as above mentioned is only depending on a single elastic buffering structure, such like the rubber bushing (400, FIG. 6 of '824), so that the formed elastic buffering is limited. One of the disadvantages is the insufficient elastic buffering in use.
Please refer to FIG. 7 of the present invention, it is illustrated the rubber bushing body (402, FIG. 8 of '824) while being deformed. Because the buffering elasticity of the above mentioned rubber bushing (400 of '824) is insufficient, the rubber bushing bodies (402, of '824) may be over loaded to break to two sections and lose the elastic buffering function once the expanding strength of the rubber bushing (400 of '824) with the multi-directional movement is larger than the limit force which the rubber bushing bodies (402, of '824) can take.
Finally, please refer to FIG. 8 of the present invention, it is illustrated another deformation structure of the rubber bushing body (402 of '824). When the expanding strength of the rubber bushing (400 of '824) with the multi-directional movement is larger than the limit of the connection of the rubber bushing body (402 of '824) and the connector (nipple 404 of '824), it may make the connector (nipple 404 of '824) be pulled out and separated from the rubber bushing body (402 of '824) so as to lose the elastic buffering function.
In conclusion, the chair structure with multi-directional moving elastic buffering has following disadvantages in use.
Firstly, the single elastic buffering structure may be formed finite elastic buffering to result in insufficient buffering elasticity and bad sitting feeling and comfort.
Secondly, when the elastic buffering is insufficient and the pulling force for moving the chair is larger than the loading of the rubber bushing body (402 of '824) being able to take, it may be broken to two sections and lost the elastic buffering function.
Thirdly, when the expanding strength of the rubber bushing (400 of '824) with the multi-directional movement is larger than the limit of the connection of the rubber bushing body (402 of '824) and the connector (nipple 404 of '824), it may make the connector (nipple 404 of '824) be pulled out and separated from the rubber bushing body (402 of '824) so as to lose the elastic buffering function.
In view of the foregoing circumstances, the inventor has invested a lot of time to study the relevant knowledge, compare the pros and cons, research and develop related products. After quite many experiments and tests, the “topple-proof buffering structure for a chair” of this invention is eventually launched to improve the foregoing shortcomings, to meet the public use.